U.S. Department of Health & Human Services; National Institute of Health; National Heart, Lung, and Blood Institute, August 2006 2011. http://www.nhlbi.nih.gov/health/educational/pad/materials/pad_extfctsht_general.html

U.S. Census Bureau, Population Division. Annual Estimates of the Resident Population for Selected Age Groups by Sex for the United States, States, Counties and Puerto Rico Commonwealth and Municipios: April 1, 2010 to July 1, 2015. Released June 2016. https://www.census.gov/popest/data/counties/asrh/2015/PEPAGESEX.html. Accessed Aug. 2, 2016.